Technical Field
The present disclosure relates to a light emitting device.
Discussion of the Background
Currently, a semiconductor light emitting device which subjects light of a light emitting element to wavelength conversion with a phosphor and emits white light by the light from the light emitting element and light from the phosphor is used as a light source of an illumination device such as general lighting, street light, or a head lamp. Of these described above, for example, for the street light and the head lamp, a light emitting device with high front luminance is required, and various light emitting devices have been conventionally suggested.
For example, Japanese Unexamined Patent Application Publication No. 2009-218274 suggests a light emitting device including a wavelength conversion layer and a reflective member for the purpose of ensuring high front luminance. The wavelength conversion layer is disposed on the upper portion of the light emitting element, converts the wavelength of light from a light-emitting element, and is formed of a light transmissive member containing a phosphor. The reflective member is disposed adjacently to a side surface of this wavelength conversion layer and a side surface of the light emitting element.
Moreover, for the purpose of improving phosphor concentration, Japanese Unexamined Patent Application Publication No. 2014-120722 suggests a light emitting device including a wavelength conversion member disposed on an upper surface of a light emitting element with a bonding layer in between, a light transmissive member disposed on an upper surface of the wavelength conversion member integrally therewith, and a light reflective member disposed along side surfaces of the light emitting element, the wavelength conversion member, and the light transmissive member.
For the purpose of reducing color unevenness on a light emitting surface, Japanese Unexamined Patent Application Publication No. 2012-156180 suggests a light emitting device including a phosphor-containing resin layer disposed on a light emitting element, and a plate-like optical layer loaded on the phosphor-containing resin layer, wherein the phosphor concentration of the phosphor-containing resin layer is different between a surrounding region of the light emitting element and a region immediately thereabove.